1. It's fantasy...they can carry a frying pan or a sword-whip or pixie-powered musket. It depends on your setting.
2. If it's in the 22nd century, is it science fiction? In which case, a laser blaster, naturally! Pew pew! But seriously, depends what level of technology you have in your world, and how combat takes place. If soldiers still have to do live close combat in your future, why? And how? See Starship Troopers, Old Man's War, and Forever War for lots of future soldier fun times.
3. "Characters, Emotion and Viewpoint" by Nancy Kress is a good one for writing any type of characters. I like books about different archetypal characters too, I think they helpful when brainstorming characters and their problems.